BELLEVUE – Drivers heading west across Lake Washington should plan for two weekends of road work in January. During the weekend closures contractor crews working for the Washington State Department of Transportation and Sound Transit will continue upgrading the operations and safety systems inside the Mount Baker and Mercer Island tunnels.

Beginning at 11 p.m. Friday, Jan. 8, the crews will reroute all westbound lanes of Interstate 90 to the express lanes between Bellevue Way Southeast and Rainier Avenue South until 5 a.m. Monday, Jan. 11.

Westbound I-90 traffic between Bellevue Way Southeast and Rainier Avenue South is routed to the express lanes.

Mercer Island traffic will need to exit westbound I-90 at East Mercer Way. There are no westbound exits to Mercer Island from the express lanes.

Drivers heading to Seattle from Mercer Island should use the 77th Avenue Southeast or Island Crest Way express lane on-ramps.

The westbound I-90 exit to Rainier Avenue South will be closed. Drivers will follow the signed detour via Fourth Avenue South and eastbound I-90.

Flammable materials will be prohibited on westbound I-90. Drivers must use alternate routes such as I-405, SR 520 or SR 522.

The I-90 Trail will not be impacted during the closure.

Special events

University of Washington women’s basketball

2 p.m. Sunday, Jan. 10

WSDOT needs help from drivers to keep traffic moving Thousands of vehicles travel across the I-90 floating bridge on a typical weekend. WSDOT needs drivers’ help to prevent regional gridlock during weekend construction work:

Know before you go: check the Seattle traffic website, call 511 for real-time travel information, and plan for delays and added travel time.

Allow extra time to travel westbound on I-90 or on alternate routes.

Ride transit, carpool or use other alternative modes of transportation.

Travel early in the morning or later in the evening, or reschedule discretionary trips.

Expect congestion on alternate routes such as I-405, I-5 and SR 520.

Key alternate routes for drivers heading to Seattle and the stadiums from the south end include SR 509, SR 599, East Marginal Way South, Airport Way South and Fourth Avenue South.

During daytime closures, drivers should expect increased congestion on local streets, especially Rainier Avenue South, Fourth Avenue South and South Dearborn Street in Seattle; and Bellevue Way Southeast in Bellevue.

Project background

The I-90 Two-Way Transit and HOV Operations project adds carpool lanes to both directions of I-90 between Seattle and Bellevue. This collaboration with Sound Transit will preserve the number of general-purpose lanes for solo drivers while adding all-day carpool lanes to I-90. Building the new HOV lanes on the outer roadway of I-90 will enable construction of Sound Transit’s 14-mile East Link light rail extension from Seattle to Redmond.